Panasonic CS-E18CKE / CU-E18CKE / CS-E21CKE / CU-E21CKE Service Manual ▷ View online
8.2.1.4. IPM (Power transistor) Prevention Control
A. Overheating Prevention Control
1. When the IPM temperature rises to 110°C, compressor operation will stop immediately.
2. Compressor operation restarts after three minutes the temperature decreases to 95°C.
B. DC Peak Current Control
1. When electric current to IPM exceeds set value of 25.0 ± 4.0 A, the compressor will stop operate. Then, operation will restart
after three minutes.
2. If the set value is exceeded again more than 30 seconds after the compressor starts, the operation will restart after two
minute.
3. If the set value is exceeded again within 30 seconds after the compressor starts, the operation will restart after one minute.
If this condition repeats continuously for seven times, all indoor and outdoor relays will be cut off.
8.2.1.5. Compressor Overheating Prevention Control
Instructed frequency for compressor operation will be regulated by compressor top temperature. The changes of frequency are as
below figure.
below figure.
8.2.1.6. Low Pressure Prevention Control (Gas Leakage Detection)
1. When the conditions listed in below table occur, the compressor stops and restarts after three minutes.
2. If this phenomenon is continuously occurring for twice within 20 minutes, all indoor and outdoor relays will be cut off.
3. This control is not applicable for deice operation.
Conditions
E18CK
E21CK
Cooling/Soft Dry
Heating
Cooling/Soft Dry
Heating
1. Compressor frequency (Hz)
86
86
102
93
2. Outdoor total running current (A)
1.5
1.5
1.5
1.5
3. Indoor heat exchanger temperature (°C)
20
25
20
25
Note: Conditions 1 and 2 needed to be happened continuously for 5 minutes.
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8.2.1.7. CT Disconnection Detection
1. Control Starting Condition
a. Total Current is below 0.74 ~ 0.94 Amp.
b. Operating Frequency is 72 Hz (E18CK), 95 Hz (E21CK) +1 and above.
c.
Continuously for 20s.
2. Control Contents
a. Abnormal signal transmitted to indoor unit after 3 minutes outdoor power is supplied. (Indoor unit stop)
3. Control Cancellation Condition
Starting condition, (1) is not fulfilled.
8.2.1.8. Low Frequency Protection Control 1
When the compressor operate at frequency lower than 22 Hz for 240 minutes, the operation frequency will be increased to 22 Hz
for two minutes.
for two minutes.
8.2.1.9. Low Frequency Protection Control 2
When all the below conditions occur, minimum value (Freq. MIN) for the frequency instructed to compressor will change to 30 Hz.
Temperature, T, for:
Cooling/Soft Dry
Heating
Indoor intake air (°C)
T
15 or T
30
T
14 or T
28
Outdoor air (°C)
T
13 or T
38
T
4 or T
24
Indoor heat exchanger (°C)
T
30
T
0
8.2.1.10. Minimum Frequency Protection Control
• During cooling operation (Anti Freezing control, soft dry) carry out the following operation.
1. During remote control setting is less than 28 deg
Indoor Fan Speed
Above Hi
minHz =
21
Above Me-
minHz =
21
Less than Me-
minHz =
18
Auto
minHz =
16
2. During Powerful ON
minHz =
22
However, when less than thermo OFF for 120 sec. continuously, the above control will be cancel.
• During heating operation, operate the followings control.
1. During Remote Control setting is less than 18 deg
Indoor Fan Speed
Above Hi
minHz =
30
Above Lo
minHz =
25
Less than Lo
minHz =
15
2. During Powerful ON
minHz =
35
However, when less than thermo OFF for 100 sec. continuously, the above control will be cancel.
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8.2.2. Protection Control For Cooling & Soft Dry Operation
8.2.2.1. Outdoor Air Temperature Control
The compressor operating frequency is regulated in accordance to the outdoor air temperature as shown in the diagram below.
8.2.2.2. Cooling Overload Control
i. Pipe temperature limitation/restriction
• Detects the Outdoor pipe temperature and carry out below restriction/limitation (Limit the compressor Operation frequency)
• The compressor stop if outdoor pipe temperature exceeds 63°C
• If the compressor stops 4 times in 20 minutes, Timer LED blinking (F95: outdoor high pressure rise protection)
• The compressor stop if outdoor pipe temperature exceeds 63°C
• If the compressor stops 4 times in 20 minutes, Timer LED blinking (F95: outdoor high pressure rise protection)
ii. Electrical part temperature rise protection control
• To prevent electrical component temperature rise during cooling overload.
• Judgement condition is by outdoor temperature (sampled every 10s).
• Control contents:
• Judgement condition is by outdoor temperature (sampled every 10s).
• Control contents:
Outdoor fan speed (switch to zone A and B minimum fan speed).
Outdoor total current (zone C) higher than the specified.
• Cancellation condition: When one of above is not satisfied.
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8.2.2.3. Anti-Freezing Control
1. When indoor heat exchanger temperature is lower than 2°C continuously for six minutes, compressor will stop operating.
2. Compressor will resume its operation three minutes after the indoor heat exchanger is higher than 10°C.
3. At the same time, indoor fan speed increase +40 rpm compared to its normal operation.
4. If indoor heat exchanger temperature is higher than 10°C for five minutes, the fan speed will return to its normal operation.
8.2.2.4. Anti-Dew Formation Control
a) Control 1
• During anti-dew formation control, compressor operates at frequency shift as shown below when indoor fan speed is less
than Me.
• This control is cancelled after started for 420 minutes, or remote control setting temperature or fan speed setting is changed.
b) Control 2
• When the following conditions occurs for 20 minutes continuously, anti-dew formation is controlled and air vane change
Horizontal vane shift to 2nd position and Vertical vane shift to center position.
1. Indoor intake air temperature is 25°C or above and less than 29°C.
2. Outdoor air temperature is less than 30°C.
3. Air vane control: Manual Horizontal Airflow and Manual Vertical Airflow.
4. Fan speed is quiet Lo.
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